Furnace



Jib-7,1925. Y 1,544,870

N. D. STEVENS FURNACE Filed July 31, 1920 2 Sheets-Sheet 1 STEVENSFURNACE Filed July 1920 2 Sheets-Sheet 2 I PatentedilhlyZlQZS. a XUNITED STATES PATENT OFFICE. I

na'rmmr. n. STEVENS, or wILxns-Bman, rnuxsnvmm, assronon *ro II. n.nnrmcx comm, or CHICAGO, more, a coaromm'rox or ILLINOIS.

ruanaca.

Application filed July 81, 1920. Serial No. 400,586.

To all whom it my'comem: J eluding elements of slightly modified con- Beit known that I, NATHANIEL D. struction; v p p I v S'rnvnNs, a citizenof the United States of Fig. 4 is a' side elevation of one of theAmerica, residing at Wilkes-Barre, in the filler bricks shown in Fig. 3,

6 county of Luzerne and State of vPennsyl- Figs. 5 and 6 are side andend elevations, 60 vania, have invented certain new and userespectively,of one of the bricks of either ful Improvements in Furnaces, of which ofthe radial arches; L

the following is a specification. 7 and 8 aresimilar views of cer- Myinvention relates to furnaces, and artam bricks of the main arch shownin Figs. ticularly to the construction of the re- 1 and 2; and

box walls. Among the objects of my in- Fig. 9- is a section throughportion of vention may be mentioned especially an imthe mam arch showinga further modified proved construction of the llning elements ,form ofone of filler a of the fire box to secure greater durability, In itsmain. features the resent construcsecond, to provide dead air spacesbetween .tion corresponds to that s own in my cothe lining elements andthe main body of. nding application Ser. No. 378,328, filed the walls,third, to'appl these-features of Q a 1, 1920,in that the bricks of themain improvements particular y' to arches of the arc are suspended' fromtransverse beams suspended type of construction. I 10 exposed to aircooling and" having at suit- 20 One of the more specific objects oftheable intervals clamps 11 which en age the invention is the provision ofa construction dove-tailed heads of tie bricks 12. etween, for arches orarch portions of convex ar-' adJa'cent rows of tie bricks extendsupercuate form, such as may be employed in posed layers of fillerbricks '13 and 14. In

positions .where it is des red to change the the constructmn shown in myprevious ap- 25 course or direction of the refractory wall, plication,the .t1eZ'b1iCkS 12 extend the full 99 by virtue of which improvedconstruction thickness of therarch, and are consequently such portionsof the arch and their supexposed at their. inner ends to the heat'ofporting members aresafeguard against dethe fire 'on the travehng grate15. Inasterioration by the heat and combustion much as nnury to theexposed face of the,

'30 products within the combustionchamber, tie brick lessens thesupportafiorded by and the component parts of the structure it totheintermediate filler bricks 14,1 have are rendered accessible andreadily interfound 1t desirable to protect the tie bricks changeable forpurposes of replacement or agalnst the dlrect heat and contact .of gasesrepair. in the fire box. 3f Other objects of the invention will beAsshown in F igs. 1, 2, 7 and8, empointed out hereinafter, indicated inthe apploy for this purpose a tile 16, preferably efided claims orobvious to one skilled of some material capable of resisting very in theart from the present disclosure. high heat, such as carborundum, andsecure 'In the accompanying drawings I'have this tile to'the fillerbrick 14 by means of 7 shown one form in which the 'invendove-tailedribs 17 on the tile which fit into tion may be embodied, but it is to becorresponding channels 18 formed in the understood that the same is herepresented fire-box face of filler brick 142. Where amfor illustrativepurposes only, and that it terial" such as carborundunr is used as afacisnot to be construed in any fashion such mg or veneer tile, certaincomphcations 45. as to limit the invention which I purport arlse fromthe fact that thlS material 1s to secure, short of its true and mostcoma good conductor of heat, and consequently rehensive scope in theart.In the drawwould transmit the tie brick substantially in'gs, which forma part of the specification, all the heat received by the facing tile,un-

Fig. 1 is a longitudinal section through less the brick were protectedtherefrom in 50 the fire box of a. furnace in which my insome way- Aneffective arrangement for vention is embodied in one form; protectin the.tie brick is a dead airspace Fig. 2 is a broken front levation 19 afiored by making the ribs 17 on the thereof; 4 tile of suflic1ent height toholdv the tile Fig. 3 is a detail view in the nature of spaced from thefire-box face of the tie a section through a portion. of an arch inbricka-slight distance. Inasmuch as the at the boiler end of the box in thedirection of the flow of the products of combustion. The lattertherefore exert a suction effect in a direction to draw a current ofcooling air in through the channelsbel0 tween the carborundum tile 16and the filler 'bricks 14, which serves to protect the latter as well asthe tie brick 12 from heat injury. It is to be observed that the facingtile 16 and 23 are independently supported, each on individual tile.Accordingly, the facing tile do not interfere with the relative movementof the other tile incident to contraction and expansion, nor are theysubjected to stresses incident to the expansion and contraction of the Fother tile such as would tend to injure them.

The construction of the facing tile for the radial arches at the hopperend and boiler end of the fire box is illustrated in en- 2 larged viewin 5 and 6. The same characteristics of construction are employed. Thesegmental bricks 20 have in like manner. undercut channels 21 in thefire-box faces thereof to receive the dove-tailed ribs 22 on the innerface of the tile 23. The latter are slightly wider than the tile inorder that their margins may meet and thus afford a continuousprotection at the inner surfaces of the radialarches.

In Figs. 3 and 4, I have shown a still further modification in that thefiller brick 14* at the fire-box face of the main arch is made slightlythicker and is provided .with flanges 24 at its opposite margins of suchextent that those of adjacent bricks meet on the downward extension ofthe midline of the tie brick 12, and thus protect the I fire-box face ofthe latter against heat injury. These flanges are preferably slightlyspaced from the fire-box end of the tie brick 12, so as to afford a deadair space 25 between the flanges and the protected face of the tiebrick.

I have also shown the filler brick slightly modified in the face thereofadjacent the outer brick 13 by depressing the outer face of the brick14" to afford a channel 26, which thus gives a greater dead air spacebetween the bricks 13 and 14 than provided in my prior construction.

In Fig. 9 the construction is substantially the same as that justdescribed, with respect to Figs. 3 and 4, except that the filler brick14 is not provided with a protective veneer tile 16, or with the channel26. A construction of this type is satisfactory where the heat of thefurnace does not run very high. In the illustrative embodiments shownand in any modifications thereof the'tile 12 and 20 may be regarded assuspension tile while the tile supported on them andproviding the fireresisting surface, such as the tile 14, 14", 16 and 23, may be termedthe facing tile.

The advantage of the construction shown will be readily recognized whenit is recalled that the fusion point of clay brick is approximately 3300F.,'and that a safe working temperature should not exceed 3000 F. \Vherethe furnace is used to burn soft coal and powdered fuel, etc., thetemperature in the fire chamber is often above the safe working point ofthe fire brick. The carborundum tile 16, however, will withstand atemperature as high as 4200-F., thus. rais ing the safe workingtemperature in the furnace approximately 1000. The construction employedfor this purpose is simple and effective. The air circulation throughthe channels 19 is not sufficient to appreciably lessen the heattransmitted to the boiler, while on the other hand it is suflicient toprotect the arch construction. These features are, of particularimportance in the radial or convex portions of the arch, as in suchparts where the course of the combustion gas is changed, there is thegreatest tendency for the refractories to spall under the combinedinfluence of the extreme heat and the errosive action of the products ofcombustion. My invention provides a con- I struction. for these portionsof the arch which is effective to fully protect the metallic supportingmembers and tosafeguard the refractories, while permitting them thenecessary freedom of relative movement to accommodate expansion andcontraction and rendering the other parts acce$ible for replacement orrepair.

Various modifications in detail of construction will occur to thosedealing with the problem, which do not depart from what I claimas myinvention.

What I claim is 1. In a furnace arch, a metal suspension beam whollyexposed for air cooling, spaced refractory tie blocks directly suspendedtherefrom, filler refractories engaged between said tie blocks andsupported thereby, and means associated with said filler blocks forprotecting the fire box ends of said tie'blocks against heat injury.

2. In a furnace arch, a metal suspension beam wholly exposed for aircoolingfspaced refractory tie blocks directly suspended therefrom,filler refractories engaged between said tie blocks and supportedthereby,

and means associated with said filler blocks &

therefrom, filler refractories engaged between said tie blocks andsupported thereby, and means carried by said filler blocks forprotecting the fire box ends of said tie blocks against heat injury.

4. In a furnace arch, a metal. suspension beam wholly, exposed for aircooling, spaced refractory tie blocks directly suspended thereflrom,filler refractories engaged between said tie blocks and supportedthereby, and means carried by said filler blocks and air spaced from thefire box ends of the he blocksto protect the latter against heat inry.5. In a furnace arch, an exposed suspension member, arch refractorieshung therefrom, spaced layers of arch brick engaging said refractoriesand supported thereby, the faces of the bricks of one layer opposed thefaces of the adjacent layer being recessed to afford an enlarged airspace between the said layers.

6. A furnace arch construction comprising in combination metallicsupporting members, wedge-shaped channelled suspension tile supportedthereon'with their side faces in contact and their end faces inangularrelationship, and facing tile engaged in the channels of the 'susnsion tile in covering relationship to their lower end and 00- operatingto form a continuous refractory wall of arcuate contour.

7. In a furnace fire box, an arch compris ing fire brick, in combinationwith a tile veneer secured brick and spacedtherefrom to form a channel,said channel having an, unobstructed opening at one end in the directionof thetravel of the products of combustion from the firebox and at itsother end to a cooling air intake.

. 8. In a fire-b0 chamber, a suspended arch forming the roof of thechamber, side walls having expansion chambers into which the ends ofsaid roof enter,- together with a protective tile facing for said arch,the tiles entering said expansion chamber at opposite sides of thefirebox, together with material in said expansion chambers serving topack the latter againstair leakage.

' 9. In furnace arch construction, in combination, metallic supportingmembers, suspension tile individually suspended thereon, and surfacetile supported on the suspension tile severally and cooperating toprovide a continuous refractory surface for the furnace arch. I

10. In furnace arch construction, in combination, metallic supportingmembers,

Jwedge-shaped suspension tile supported suspension tile having endthereon, said to the fire-box face of said 7 said tile engaging faces inangular relationship, surface tile supported on the suspension tile andassociated to tory surface, portions of said surface tile being spacedfrom the supporting tile to afford air conducting channels following thecontour of the arch surface.

11. In furnace arch construction, in combination, metallic supportingmembers, wedge-shaped suspension tile supported thereon in angularrelationship, and surface tile supported on the suspension tileseverally, said surface tile being arranged to form a continuousrefractory surface on the arch.

12. In furnace construction, in combination, a), plurality of archsup-port'ng bars disposed in substantially horizontal relationship, aplurality of tile supporting memto bers associated with said archsupporting bars, said tile supporting members having tile engagingportions arranged in arcuate relationship, suspension tile suspendedfrom said arch supporting bars and said tile supporting members, andrefractories supported on said suspension tile' and covering their endfaces, said refractories being associated to form a substantiallyhorizontal arch port-ion supported by the arch bars and a contiguousconvex arcuate arch portion supported by the tile supporting members.

13. In furnace arch construction, in combination, associated supportingmembers having ar'cuately arranged tile engaging portions, suspensiontile supported thereon, and refractories suspended on the suspensiontile and covering their end faces, said refractories being associated toform a convex arcuate portion of the furnace chamber.

14. In furnace arch construction, in combination, metallic supportingmembers, wedge-shaped mlspension tile supported thereon, andrefractories suspended on the suspension tile with their outer surfacesassociated to form- 'a convex heat resisting arch;

15. In furnace arch construction, in combination, a plurality ofassociated supporting members having tile engaging portions,wedge-shaped suspension tile retained by portions, said suspension tilebeingprovlded with channels extending intermediate their convergingsides, and refractories engaged in said channels and suspended from saidsuspension tile in association to form a convexheat resisting archportion between the suspension tile and the. furnace chamber. r

In testimony whereof I have signed my name to this specification.

NATHANIEL D STEVENS.

form a continuous arcuate refrac-

